This invention relates to an induction heater wherein material is heated by contact with an inductively heated heating element.
Bulk or continuous flow heaters are employed as dryers or calciners. Typically, a heating member contacts material to be heated so that heat is efficiently transferred from the heating element to the material to be heated. Some degree of mixing action to improve contact can also be incorporated with the heating action of the heating element, for example by providing the heating element with fin members, as a result contact between the heating element and the material to be heated is enhanced. However, it is preferably to provide substantially uniform heating of the material to be heated. Consequently, means aree required to supply heat uniformly to the heating member and the fin members thereof.
The supply of heat to the heating element is particularly problematical where fin members are included. Known dryers incorporate heating by means of gas jets or hot fluid. Consequently, in order to heat such fin members complicated supply tubing must be engineered into the fin member. It is also known to adapt the fin member to enhance the mixing resulting from movement of the heating element. This only serves to further complicate the design of the fin member. Particular problems are encountered with rotary drum dryers and calciners since it is necessary to incorporate rotary couplings for supply of the hot fluid or gases. Consequently, there are a number of drawbacks for heating the heating element of known bulk or continuous flow heaters.